Darkmoon Buff in Proving Grounds

You can get an extra 10% of your main stat as a buff from Darkmoon Festival that will not get removed in Proving Grounds it states that it get's removed in dungeons and raids and i suppose it should on scenarios too but it doesn't get removed.

The name of the npc is Sayge and here are the answers to get a specific buff from him:

• Dark Fortune of Agility - Agility increased by 10%: (Answers 3&3)
• Dark Fortune of Armor - Armor increased by 10%: (Answers 1&3, or 4&3)
• Dark Fortune of Damage - Damage increased by 1% to 10%: (Answers 1&1)
• Dark Fortune of Intelligence - Intelligence increased by 10%: (Answers 2&2, or 4&1)
• Dark Fortune of Resistance - Magical resistances increased by 25: (Answers 1&2, or 2&3)
• Dark Fortune of Spirit - Spirit increased by 10%: (Answers 2&1, or 4&2)
• Dark Fortune of Stamina - Stamina increased by 10%: (Answers 3&1)
• Dark Fortune of Strength - Strength increased by 10%: (Answers 3&2